Cheomseongdae Observatory Construction

Cheomseongdae, an astronomical observatory, was constructed in Gyeongju during the second year of Queen Seondeok's reign in the Silla Kingdom around 633 CE. The 9-meter granite structure contains 362 stones arranged in 27 circular layers, with a south-facing window. Astronomers used it to track celestial movements, predict weather patterns for agriculture, and interpret celestial omens. The design incorporated mathematical and astronomical principles. The structure has survived approximately 1,400 years of earthquakes and weather events.